WARNING: After removing the wall plate, if you find that it is mounted on a junction box (e.g. a box similar to one behind a light switch or electric outlet), 240 volts circuit may be present and there is a danger of electric shock. Please consult a qualified electrician.
WIRE LABELLING
nIf your old thermostat wall plate has more than two wires con- nected to it, then you will need to label the wires. First look for LETTER near each terminal where a wire is connected. These terminals and markings may be on either side of the wall plate.
oDisconnect and identify each wire.
pYou may wish to tape the wires to the wall to keep them from slipping through the hole in the wall. If the hole in the wall is larger than necessary, fill it in order to prevent hot or cold air to penetrate the thermostat. In this manner, the thermostat will behave perfectly.
CHOOSING A LOCATION
Note: For a new installation, choose a mounting location about five feet (150 cm) above the floor in an area with good air circulation and away from:
Drafts or dead air spots, Air ducts, radiant heat from the sun or appliances, Concealed pipes and chimneys.
Mounting the thermostat onto the wall
nRemove completely the slide door of the thermostat. o Unscrew and remove the cover over the connector.
pMark the holes posi- tion and align the wire
coming from the wall in the hole beside the connectors.
q Drill two holes and insert the plastic anchors carefully into the holes until they are flush with the wall.
rFasten securely the thermostat to the wall with the two (2) screws.
DISPLAY IN °C OR °F
After the installation of the battery, if you want to change unit of the degree displayed, follow these instructions (see the illustration):
n From the back of the thermostat, unscrew the cover.
o For the °C display, the jumper in JP1 is installed.
pFor the °F display, the jumper in JP1 is removed. q
r Press on the reset button.
CONNECTING THE LABELLED WIRES TO THE THERMO- STAT
nConnect the system wires to the terminals according to the wir- ing diagram shown in the section “wiring diagram”.
WARNING: Do not remove the jumper between terminals Rh and Rc unless otherwise specified.
oPush on the wires in the wall and replace the cover over the connectors.
pInstall two (2) “AA” size batteries into the battery compartment.
qTurn on the main switch of the system. The thermostat is ready for use.
WIRING DIAGRAM
The TH123 thermostat can be used with any single stage heating and cooling system. You cannot directly use this thermostat on mul- tiple stages heating or cooling system, millivolt system, heat pump or 240 VAC control system. It can control some of those systems by installing an isolation relay and a
HEATING SYSTEM TYPE
The heating system type selector is located below the wire connec- tor. Start first by keeping the selector at default position Hg. If the fan switch is at FAN AUTO position and the fan doesn’t start when the thermostat turns on the furnace, place the type selector at posi- tion He.
2-WIRE HEATING SYSTEM
nConnect the heating relay to terminal W.
oConnect the 24 VAC transformer to terminal Rh.
3-WIRE HEATING SYSTEM WITH FAN CONTROL
nConnect the heating relay to terminal W. o Connect the fan relay to terminal G.
p Connect the 24 VAC transformer to terminal Rh.
4-WIRE HEATING AND COOLING SYSTEM
nConnect the heating relay to terminal W. o Connect the cooling relay to terminal Y. p Connect the fan relay to terminal G.
q Connect the 24VAC transformer to terminal Rh.
